Speaker
Description
The disposal of spent coffee grounds (SCG), a biomass waste produced from coffee brewing, poses a significant environmental challenge due to its high organic content and large quantities. To address this issue, a valorization approach to convert SCG into bio-oil through pyrolysis and to extract oleic acid, the predominant fatty acid in SCG, from the pyrolyzed bio-oil has been explored. A Box-Behnken experimental design was performed to optimize the pyrolysis yields using three key process parameters including SCG particle size, pyrolysis temperature, and nitrogen flow rate. Based on the statistical analysis results, all three parameters significantly influenced bio-oil yield, while only temperature and SCG particle size were the primary factors affecting fatty acid concentration. The optimal conditions determined in this study were SCG particle size of less than 0.25 mm, a pyrolysis temperature of 550 °C, and a nitrogen flow rate of 0.5 L/min, achieving a bio-oil yield of 34.13%. Additionally, oleic acid was extracted from the bio-oil through liquid-liquid extraction using hexane, which can be processed further, offering potential for various chemical applications. This study demonstrates a viable method for SCG waste valorization, contributing to environmental sustainability.
